Tutorial using document class

hello, hope you can help me

Im trying to follow a tutorial which i believe requires you to use the document class to generate a flickr gallery in flash. the problem is it give you the code but does show you what to do with it.

Ive looked into document classes but looks like you can only use one? and the tutorial has two (Flickr_viewer.as) and (Load_image.as)

ive done all the tutorial says, like changing the API key and NSID, but dont have a clue what to do now

tutorial can be found here

thanks alot for your time,